Concentration of ore



F. G. GASCHE.

CONCENTRATION OF ORE.

APPLICATION FILED MAR. 5, 191a.

Patented Nov. 23, 1920.

2 $HEETSSHEET I.

F. G. GASCHE.

CONCENTRATION OF ORE.

APPLICATION FILED MAR. 5, 1918.

1 ,359,496, Patented Nov. 23, 1920.

. N v I A N r UNITED srarrs PATENT err-ice.

FERDINAND iGASCHE, OF CHICAGO, ILLINOIS.

CONQENTRATION. OF ORE.

esoaae.

Application filed March 5, 1918.

To all whom it may concern:

Be it known that I, FERDINAND G. GAscHE, a citizen of the United States,and. a resident of Chicago, county of Cook, and State of Illinois, haveinvented certain new and useful. Improvements in and for theConcentration of Ores, of which the-following is a specification.

My invention relates to the treatment of ore to effect the separation ofthe metal particles and metal-bearing portions from the lighter ganguewhich comprises the greater bulk of the ore.

It is customary to ship ores direct from the mines to largeconcentrators, smelters, or cyanid extractors, where the values arerecovered and either purchased or returned to the miner. The initialcost and the operating expenses of such plants, and the low efficiencythereof when operated on a small scale, practically preclude any othermethod of ore disposal. Furthermore, the present cost of concentratingore and recovering the values therefrom, makes it unprofitable v tohandle and ship any other than comparatively rich ores, with the resultthat lowgrade ore remains unmined or if mined is treated as waste andleft upon the dump at the mine; and also, rich ore deposits remainunworked because too far distant from a smelter or extractor, or forlack of trans.

portation facilities.

The object of my invention is to overcome these difficulties by enablingmen of little skill as metallurgists, and with little labor, to handleboth high and low-grade ores and speedily, efiiciently and economicallyconcentrate the valuable parts thereof, in the immediate vicinity of themine or dump; and where with little added expense the concentrates maybe refined, or because of the reduction in bulk may be profitablyshipped even to distant points for that purpose.

My invention comprises a novel concentrating process and apparatustherefor, all as hereinafter described and particularly pointed'out inthe claims:

The invention will be readily understood on reference to theaccompanying drawings which form part of this specification and inwhich: Figure 1 is'a diagrammatic elevation of a concentrating plantembodying my invention;-Fig. 2 is a sectional detail of one of the airguns which 1 employ ;-Fig. 3 is a view of the nozzle on the parting lineSpecification of Letters Patent.

Patented Nov. 23, 1920.

Serial No. 220,427.

X-X of Fig. 2 viewed in the direction of the arrow A;-and, Fig. 4: is alike view in the direction of the arrow It should be understood at theoutset that these drawings depict only the best apparatus which I havethus far devised, containing various novel features and combinations,but are not intended to imply that my invention is restricted thereto.

Fig. 1 illustrates a mill and power house, 2, near which is theconcentrating floor, 3, covered by a long shed, 4:. The house, 2,contains a suitably driven conveyer, 5, for feeding ore to the mill orpulverizer, 6. The latter is driven by .an engine or motor, 7. Thepulverized product leaves the mill through a swinging spout, 8, adaptedto deliver the pulverized ore first to one and then to another of thetanks, 9. These tanks are closed at the top by means of hopper valves,10. The bottom of each tank is in the form of a hopper and leadingtherefrom V is adown-spout, 11, which delivers into a mixing head, 12.This head, as hereinafter explained, contains devices for dischargingthe pulverized ore from the tanks into respective mixing chambers, 13.Each of these mixing chambers has an elbow, 14:, which communicates withthe gun-or nozzle, 15, the details of which, in the preferred form, willbe explained hereinafter. The house, 2, also contains an air compressingor blowing engine, preferably a turbine-blower, 16, of a two-stage type.The outlet pipe, 17, there of is connected to the'system at pointswithin the tanks, 9, within the heads, 12, and preferably also withinthe nozzle, 15, as better explained hereinafter. It will be understoodthat the two heads, 12, and their elbows preferably join a single gun ornozzle, 15; that is, the plurality of tanks or reservoirs comprise meansfor continuously feeding the crushed ore to the gun 15.

The gun, 15, extends through the wall, a, of the shed, 4-, andpreferably is positioned to discharge the ore horizontally across theconcentrating floor, 8. Obviously the gun may be aimed up or down fromthe horizontal and thus is a change sometimes made for the purpose ofcompensating variations in the quality of the pulverized ore.

The floor, 3, may contain a simple flat surface, but preferably containsa plurality erably equipped with outlet conduits or tion comprehends thereturn of the poor or" low grade concentrate from the hopper, 19, to themill to be reground and again discharged through the gun, 15. The shedhas a closed far end, 4", which is preferably inclined, as shown. Theroof of the shed,

or, if desired, the floor thereof, contains pressure relief openings,21, and save for the necessary doors and windows, these may be the onlyopenings in the walls of the shed.

Referring now to Figs. 2, 3, and 4, for the details of the preferredform of my novel gun or nozzle. the parts before referred to may beidentified as follows, to-wit: The tank, 9, the down-spout, 11; thehead, 12; the elbow, 14; the gun or nozzle, 15; and the blower pipe, 17.One branch, 17, of the pipe, 17, communicates with the pipes 22 and 23,containing respective valves 22 and 23. The pipe, 22, leads-through theside of the tank, 9. and is bent downwardly so that it substantiallyenters the down-spout, 11. At the lower end of the down-spout is acasting, 12', which contains in its central bore a tube, 24, having atits lower end a valve seat, 25, and also a conical surface, 26. A valve,27, coacts with the seat, 25, to regulate the flow of ore from the tank.This valve is carried by a stem, 28, having a hand wheel, 29, on theexterior of the elbow portion, 13, 14. The upper part of the part 13contains an enlarged cavity, 30, which is continued in the cavity, 31.of the intermediate casting or member, 12", of the head, Thisintermediate part contains an adjustable conical ring, 32, which ismovable toward and from the cone, 26. to provide the conical airpassage, '33; WVithin the part, 12, is an annular cavity. 34, whichcommunicates with the pipe, 23, andhence with the conical passage, 33. Acombining tube, 35, presents its large end to the lower end of theelbow, 14. The small end of the combining tube,- 35, delivers into thepipe. 36, one section, 36, of which preferably is flexible. To theforward end of the pipe, 36, I connect a second combining tube, 3.7 thetip of which is formed by a nozzle, 38. Attached to the part, 37, is ahead, 39, which contains a central cavity, 40, and also an annularcavity, 41. The second branch, 17", of the blower pi e, 17, communicateswith the cavity, 41. face plate, 42, closes the end of the head. 39,leaving, however, a narrow annular crack or opening, 43, whereby asagnacommunication is established between the cavity, 41, and the cavity, 40.A threaded opening, 43, contains a nozzle plug, 44,

which has a specially formed conical bore, 45, which is in exact axialalinement with the tip, 38, and the tube, 37. Attention is called to theslight enlargement or flare, 45, at the inner. end of the bore, 45. Abridge arm, 42', that is integral with the plate, 42, contains a centralbore, 4 which holds the nozzle, 38, in axial alinement with the tube,37, and in firm abutment with the end thereof. I have thought itunnecessary to refer in detail to the several bolts and flanges wherebythe several members are joined. The forms, dimensions, and relations ofthe parts, 37, 38, 45 and "45, will be explained in the course of thedescription of the process which I carry out by aid of theapparatusdepicted.

My novel process is capable of very brief explanation, as follows: Bymeansof a suitable Inili, 6, the ore as it comes from the mine or dumpis pulverized, granulated or powdered with substantial uniformity. Thedegree to which pulverization should be carried is determined by thecharacter of the ore, but in many-cases it is suflicient if thepulverized ore is fine enough to pass through a twenty-mesh screen; andin practically all cases a pulverization corresponding to a forty-meshscreen will prove sufli cient. Finer pulverization ordinarily is tooslow and too expensive and also makes a slower precipitation of the ore.Obviously, part of the ore will be reduced to a still finer state,leaving the larger particles of the maximum sizes indicated.

Compressed air from the blowing en ine, 16, flows through the nozzle orgun, l5. Ihe pulverized ore which is furnished by the mill is fed intothis stream of air and taking on approximately the velocity of thestream of air is thus ejected or discharged from the gun, 15. Inpractice a substantially uniform velocity is imparted to every particleof the ore, and all of the particles leave the mouth of the gun ornozzle, 15, at a substantially uniform and very high velocity. Thevelocity thus imparted would afford each particle of the ore a maximumtrajectory of many tlmes the length of the shed, 4, were it not for theforce of gravity and the baffling or interferingeifect of the air oratmosphere in the shed. Due to such impedance, the lighter particles ofgangu e are caused quickly to lose velocity and .to settle upon theconcentrating floor at points not far remote from the mouth of the gun,15. Particles of metal, on the other hand, being heavier, for a longertime resist the impeding action of the air and carry nearly or quite tothe end of the shed before settling upon the floor. Other particles ofgangue which are burdened with small particles or the purpose ofaccentuating the reaction of the .air in the shed against the particles,whereby T secure a clear and distinct separation of the particlesaccording to respective masses and shapes, and enable even a veryslightly burdened particle of gangue to penetrate the shed to a pointbeyond that to which the largest particle of unburdened gangue canproceed. With this as a measure of required service of the gun, it is asimple matter to ascertain the degree to which the ore needs bepulverized and the pressure of air which needsbe maintained in thenozzle or gun.

In dealing with ores which contain several metals in a native or purestate, or substantially such so far as concerns the respective speclficgravities of .the several metals or metal compounds, it is possible bythe describedmeans to secure a closely approximate clear separation ofthe several metals upon the floor of the space or hopper, 20. This 1have indicated by showing, in dotted lines, several separate troughs orhoppers, 20', in the floor portion, 20. Beginnlng at the far-end of theshed, these troughs may be taken to re resent a series of metals ofdifferent speci c weights, such as platinum, gold, lead, silver, etc.However, as a rule, it is sufficient to collect all of the-rlch or heavyconcentrates in the'hopper or floor section, 20, leaving to the'metallurglst the usual task of refining and separating the same bychemical means, with or without the aid of heat. It will be understoodthat the great bulk of the pulverized ore, to-wit, the gangue proper,hopper, 18. The discharge of the hopper, 18, may be through the wastecondult or tunnel, whence the gangue is removed to a spo l bank. The lowgrade or poor concentrate is deposited in the intermediate hopper, 19,

from whence it may be taken for direct reduction by the metallurgist;but preferably 1 discharge the poor concentrate into the re-- turn duct,19, and thence carry it back to the mill, 6, or to a separate mill ifdesired, to be re-ground, and again projected through the concentratinggun or nozzle, 15, whereby a further separation of the metals-from thegangue is secured, with a view to lessening the work of themetallurgist. Obviously a considerable volume of air is discharged intothe shed, 4, and while it is desirable to maintain a slight pressuretherein, whereby to increase the impeding action of the air upon theprojected particles from the gun, there is of course a practical limitwhich must be observed, both to avoid disis deposited in the large--ruption of the walls of the shed, and a too great back pressure at themouth of the gun;

hence the provision of the valved vent or' vents, 21, whereby asubstantially constant low pressure condition may be maintained in theshed. v To avoid loss of extremely fine particle of metal, the ventspreferably are arranged approximately above the gangue hoppers, beyondwhich point the heavy particles are sure to be projected. This manner ofventing the' shed is attended by the advantage of the banking of the airin the closed end of the shed, for the more certain precipitation of themetal particles and heavily loaded pieces of gangue after they pass overthe floor sections or hoppers, 18 and 19.

Lest it be thought that this process, entails the expenditure of muchforce in the compression of air, 1 will explain that an air-gagepressure of considerably less than forty pounds in the gun, 15,accomplishes the projection of the metal particles to-distances ofupward of one hundred feet while the gangue particles are seldom foundbeyond fifty feet, and which thereforeis fully adequate to theaccomplishment of the separating or concentrating efl'ec't heredescribed. The apparatus hereinbefore described is admirably suited tothe performance of the several steps of my process, being an appa-,ratus which 1 have devisedfor this specific purpose. 'The operationthereof is as follows: It will be understood that there is a top closureor valve, 10, for each tank, and also a bottom closure or valve, 27, foreach tank. When filling a tank from the mill, the valve, 10, is ofcourse open, while the valve, 27, is closed. When the tank, 9, issubstantially filled with pulverized ore, the valve, 10, is closed.Thereupon compressed air from the pipe, 17, is admitted to the tankthrough the -pipe, 22, and preferabl also tot-he top of the tank througha branc pipe, 22". The maximum pressure of the system, say sixty-fivepounds absolute pressure, is thus placed upon the material in the tank,9. Then after closing the discharge valve, 27, of the (other tank, Iopen the like valve 27 of the tank which has been filled and put underpressure; at the same time opening the valve, 23, belonging to themixing head,'12, Thereupon the pulvenzed ore under compulsion ofpressure in the tank, 9,

and aided by gravity and the exit of air from the pipe, 22,

' the particles suspended in the stream of'air.

- sponding to that pressure.

combining'tube or conical passa e, 35. Due to the shape of thispassage,'t e pressure energy of the stream is in part converted intoVelocity energy and the particles of ore take on a higher velocity.Entering the communicating pipe, 36, at this velocity, the stream nextencounters the second combining tube, 37, wherein the velocity of theparticles is again augmented. In consequence, the stream emerges fromthe tip, 38, at a pressure considerably lower than the initialorstarting pressure, but at a high velocity. To be exact, the pressureat the tip, 38, under the conditions of initial velocity developedapproximates fifty-eight per cent. ofthe initial pressure following thelaw of maximum efilux and has a velocity corre- If it were possible toattain a suficient velocity it might be feasible to project theparticles direct from the nozzle tip, 38; dispensing with the head shownthereon, but a stream projected from such a nozzle tip, due to immediateexpansion into the atmosphere, setsmp detrimental conflicting movementsamong the particles, robbing some thereof of the true trajectories whichshould be given them if the best concentrating effects are to, besecured. The head, 39, which I have invented, and the pressure of airwhich I use therein, not only suppress this objectional action, but alsooperate greatly to increase the linear velocity of The first essentialof this head comprises the secondary nozzle tip and mouth, 45, in theform of a conical passage, the inner end of which is of the samediameter as the tip openingofthe nozzle, 38, and the large end ofwhich'is outward. The function of this conical passage, whether or notforming a direct, or as shown indirect, continuation of the reverselytapered tip, 38, is to restrict the lateral expansion of the stream ofair and thereby necessitate the linear expansion thereof; wherebyfurther velocity' is imparted to the particles after leaving the tip,38. If. it were not for the outwardly flared passage, 45, the air wouldbe.

permitted to expand abruptly on leaving the tip, 38, and the consequenceof such uncontrolled expansion would be the deflection of some of theparticlesfrom their direct linear paths. By thus limiting the lateralexpansion to that simple degree which directly responds to the drop ofpressure 00- casioned by the unrestricted linear expansion, I am able toconvert the pressure energy of the stream into velocity energy andmotion, which is the force desired for the propulsion of the particles.Thus I secure the highest speeds derivable from the initial or startingpressure at the pumping en ine or blower.

or the best functioning of the outwardly enlarged conical passage ormouth, 45, and for the preservation thereof against the abrading actionof the particles of ore, I provide means for two other purposes, towit',means to prevent the lateral expansion or enlargement of the jet as itemerges from the tip, 38, and, second, means to defend the walls of theconical passage, l5, from the impact of the particles of ore which passthrough it. These purposes I accomplish through the employment of theair chamber, 4E0, by the employment of a space or gap, 40', between thetwo parts, 38 and 4a, and by admitting air under pressure to thechamber, 40, through the crack, 43, leading from thespace, 41. Thevalve, 17, which is included in the pipe branch, 17', is preferably apressure reducing valve, whereby the maximum pressure in the supplypipe, 17, is reduced in the chamber, ll), and made to equal the staticpressure in the stream which emerges from the nozzle, 38. Upon 'openingor freeing the valve, 17, therefore, air is admitted to the chamber, 40,at the stated pressure. This compressed air from the chamber, 40, findsescape in conjunction with and as an envelop for the jet which emergesfrom the tip, 38. To facilitate the forming of this air-envelop aroundsaidjet, and within the passage, 45, 1 preferably reversely bevel theintake end of said passage, 45, as shown at 45. Obviously the emergingjet cannot expand within the gap, 40, for the reason that it isencompassed by an atmosphere of the same pressure. Obviously also, asthe air from the chamber, 40, finds exit through the passage, 4-5, theenvelop which it forms upon theinitial jet is preserved directly uponand against the walls of the conical passage, 45. T11 this manner, theinitial jet is prevented from expanding suddenly; also, is limitedsubstantially to linear expansion within the passage 45; and the wallsof said passage are lubricated by the added envelop 110 or air and thusare protected against abrasion by the particles within the jet.

it will now be understood that air composing the jet is allowed toexpand substantially down to atmosphere by the time it 115 emerges fromthe passage, 45, and though it preserves its velocity, it is robbed ofits capacity to disperse or laterally disturb the particles which itcontains in suspension. It will also now be understood that by means 120of the compound nozzle here depicted, l secure a very valuableaugmentation of the velocity of the particles of ore and what is ofgreat practical value, secure this effect by the expenditure of littleforce and conthe internal chamber, 40,

one hand; or an excessive lateral expansion and concurrent lateral dsplacement of par ticles on theother hand; wherefore, it is desirablethat the exact predetermined shape shall as long as possible bepreservedagainst an abrading or cut action which would chan e its shape.

By way 0% example, drawn to accord with a mountain altitude and anatmospheric pressure of ten and one-half pounds, it may 'be stated thatan initial pressure of sixtyfive pounds absolute in the blower pipe 17,and hence at the openings of the pipes, 22 and 23, affords a pressureclosely approximating thifty-eight pounds absolute at the tip, 38; andin such cases the reducing valve, 17, is adjusted to maintain the samepressure, 'to-wit, thirty-eight pounds absolute in of the nozzle head.

Under these conditions the conduit between the elbow,.1d, and the tip,38,'may be re duced to a length inches, and yet admit of theattain-mentor maximum'velocity by the particles therein. ln practice, Iprefer that this dimension shall be increased one or more times as afactor for safety as well as for mechanical convenience. With theequipment shown and at the pressures indicated, the air 1s expandedsubstantially to atmosphere on emergence from the nozzle, 45, and to theparticles held in suspension therein, there 1S 1111- parted asubstantially uniform velocity of about seven hundred feet per second.

My invention is not, limited to the employment of air as the vehicleforcarrying and expelling the pulverized material, for it will be evidentthat compressed gases may be substituted; and likewise superheated steammay be used with substantially the same results as the gun or nozzle isconcerned, but with the disadvantage of a wet concentrating shed due tothe condensation of the steam therein. l desire also that it shall beunderstood that my invention is applicable to materials other than ore.

As used in the claims the term separating velocity means a velocity suchthat when the material is projected against a,

given atmosphere, a clear separation between the particles is obtainedaccording to mass and size, articles of small mass and size being founrelatively close to the point of projection and thoseof relativelylarge.

mass and size being found in a remote positlon.

In the claims the term separation atmosphere means the atmosphere intowhich the ore stream is discharged for separation of the particles.

of approximately eighteen ticles is prevented.

rious particles of a tion atmosphere.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

l. The improvement in the art of concentrating ores that consists ininitiating an ore particle laden aeriform stream at a given velocity andstatic pressure, discharging same into a confined atmosphere havingsubstantially the same static pressure as that of the dischargingstream, whereby lateral dispersion of the ore particles is prevented,thereafter converting said static pressure of the stream into kineticenergy, thereby imparting high velocity to the ore particles and inissuing the high velocity stream against the separation atmosphere.

2. The improvement in the art of concentrating ores that consists ininitiating an ore particle laden aeriform stream at a given velocity andstatic pressure, discharging same into a confined atmosphere havingsubstantially the same static pressure as that of the dischargingstream, whereby lateral dispersion of the ore particles is prevented,thereafter converting said static pressure of the stream into kineticenergy, thereby imparting high velocity to the ore particles and inissuing the high velocity stream against the separation atmosphere inthe form of a substantially unidirectional jet.

3. The improvement in the art of corn centrating ores that consists ininitiating an orc particle laden aeriform stream at a givenvelocity andstatic pressure, discharging same into a confined atmosphere havingsubstantially the same static pressure as that of the dischargingstream, whereby lateral dispersion of the ore particles is prevented,thereafter converting .said static pressure of the stream into kineticenergy, thereby imparting high velocity to the ore particles and inissuing the high velocity stream against the separation atmosphere atsubstantially separation atmospheric pressure,whereby'lateral'dispersion of the ore par- 4. The improvement in the artof concen-' trating ores that consists in initiating an ore particleladen aeriform stream at a given velocity and static pressure and withthe vagiven stream-cross section all moving at substantially the samevelocity, thereafter greatly increasing the velocity of the ore stream,meanwhile maintaining the substantial equality of movement of therespective particles cross sectionally of the stream, and 1n issuing thehigh velocity ore, stream against the separa- 5. The improvement in theart of concentrating ores that consists in initiating an ore particleladen aeriform stream at a given velocity and static pressure and withthe various particles of a given stream cross section all moving atsubstantially the same velocity, thereafter greatly increasing thevelocity of the ore stream, meanwhile maintaining the substantialequality of movement of the respective particles cross sectionally ofthe stream, and in issuing the high velocity ore stream againsttheseparation atmosphere in the form of a substantially unidirectionaljet.

6. The improvementin the art of concentrating ores that consists ininitiating an ore particle laden aeriform stream at a given velocity andstatic pressure and with the various particles of a given stream crosssection all moving at substantially the same velocity, thereaftergreatlyincreasing the velocity of the ore stream, meanwhile maintainingthe substantial equality of movement of the respective particles crosssectionally of the stream, and in issuing the high velocity ore streamagainst the separation atmosphere at substantially separationatmospheric pressure.

'3. The improvement in the art of concentrating ores that consists ininitiating an ore particle laden aeriform stream at a velocity ofseveral hundred feet per second and at a given static pressure,discharging same stantially the same static pressure as that of theinitiated stream, and thereafter increasingthe velocity of the oreparticle laden stream to upward of 500 feet per second and in issuingsame against the separation atmosphere in the form of a substantiallyunidirectional jet.

'9. The improvement in the art of concentrating ores that consists ininitiating an ore particle laden aeriform stream at a velocity ofseveral hundred feet per second and at a given static pressure,discharging same into a confined atmosphere having substantially thesame static pressure as that of the initiated stream, and thereafterincreasing the velocity of the ore particle laden stream uplocity ofseveral hundred feet per second and at a given static pressure,discharging same intoa confined atmosphere having substantially the samestatic pressure as that of the initiated stream, and thereafterincreasing the velocity of the ore particle laden stream to one of atleast 700 feet per second and in issuing it against the separationatmosphere.

11. The improvement in the art of COI1C1I trating ores that consists ininitiating an ore particle laden aeriform stream at a velocity ofseveral hundred feet per second andat a given static pressure,discharging same into a confined atmosphere havingsubstantially the samestatic pressure as that of the initiated stream, and thereafterincreasing the velocity of the ore particle laden stream to one of atleast 700 feet per second and in issuing it against the separationatmosphere n the form of a substantially unidirectional 12. Theimprovement 1n the art of concentrating ores that consists in initiatingan ore particle laden aeriform stream at a velocity of several hundredfeet per second i and at a given static pressure, discharging same intoa confined atmosphere having substantially the same static pressure asthat of the initiated stream, and thereafter increasing the velocity ofthe ore particle laden stream to one of at least 700 feet per second andin issuing it against the separation atmosphere at substantiallyseparation atmospheric pressure.

13. The improvement in the art of concentrating ore that consists ininitiating a low velocity ore particle laden aeriform stream, thereaftergreatly increasing the velocityof the ore particles and discharging themagainst the separation atmosphere, and in maintaining the ore streamagainst lateral dispersion While it is being accelerated and as itdischarges into the separation at mosphere.

In testimony whereof I have hereunto set my hand this 2d day of March,1918.

FERDINAND G. GASCHE.

